When you send a long prompt to Copilot in Microsoft 365, the service may return an HTTP 502 Bad Gateway error. This error appears as a blank screen or a browser error page instead of Copilot’s response. The cause is a timeout or overload on the backend server that processes your request. This article explains … Read more
When you try to sign in to Copilot, you may see the error AADSTS700016 with the message Application Not Found in Tenant. This error means Azure Active Directory cannot locate the Copilot application registration in your Microsoft 365 tenant. The issue typically occurs after a tenant migration, a misconfigured enterprise application, or when the required … Read more
When you use Copilot in Microsoft Teams, a HTTP 504 Gateway Timeout error suddenly appears and stops your workflow. This error means the upstream server that processes your Copilot request did not respond within the allowed time window. The root cause is usually a network bottleneck, a misconfigured firewall, or an overloaded Microsoft 365 backend … Read more
You open Microsoft Edge and click the Copilot icon, but instead of a chat window you see a message that your token has expired. Refreshing the page or restarting the browser often brings back the same error, creating an endless loop that blocks access to Copilot in the sidebar. This problem occurs because the authentication … Read more
When you try to use Microsoft Copilot in a tenant where you are a guest user, you may see error AADSTS90072. This error means Azure Active Directory cannot authenticate your account because the user belongs to an external tenant. The message typically reads: “User from external Azure Active Directory tenant is not supported.” This article … Read more
When you try to sign in to Microsoft Copilot, you may see an error message about a WS-Federation sign-in failure. This error prevents Copilot from connecting to your Microsoft 365 tenant and blocks all Copilot features. The failure typically occurs because of a misconfigured identity provider, an expired federation certificate, or an incorrect domain federation … Read more
You try to open Copilot on your iPhone or Android device and see an error message saying access is blocked. This usually happens because your organization uses Conditional Access policies in Microsoft Entra ID to control which apps and devices can reach Copilot. These policies can block mobile access even when the desktop version works … Read more
When you try to sign in to Copilot in Microsoft 365, you may see error AADSTS50105. This error means the user account is not assigned to the required license or application role. The error prevents access to Copilot features in apps like Word, Excel, and Teams. This article explains the root cause and provides step-by-step … Read more
When you upload a file to Copilot in Microsoft 365, you may see an HTTP 413 error that stops the process. This error means the server rejected the file because its size exceeds a defined limit. The root cause is typically a restriction in the Microsoft 365 tenant configuration or a local proxy setting that … Read more
When you open the Microsoft 365 admin center to configure Copilot, you may see a red error banner that reads “Service Principal Not Found.” This error prevents you from enabling Copilot features or managing data source permissions for your tenant. The root cause is a missing or misconfigured service principal object in Microsoft Entra ID, … Read more